These brilliant pictures capture the personnel from 21 Engineer Regiment, 4th Battalion, Parachute Regiment, 2nd Battalion the Royal Anglian Regiment and 8 Engineer Brigade.
They took part in exercise Hypogeal Bear on Monday, testing new equipment in the city and below the ground in tunnels.
The challenging operation took place in sweltering heat, as temperatures reached 30C.
It's part of Project Croker, a series of experiments to improve understanding the complexity of operations in cities.
Take a look behind the scenes, courtesy of YEP photographer Bruce Rollinson:
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A second operation will take place on Wednesday - Exercise Highrise Poacher - which will be an urban raid
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It's part of Project Croker, a series of experiments to improve understanding the complexity of operations in cities
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Sergeant Dale Mottley said: "The manoeuvre through Leeds was quite difficult. The route was testing on the foot, especially with kit and equipment that had never been tested in that environment.
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"It's been quite trying once we got out into the open with the heat beating down on us.
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“Within the tunnel complex it’s not too bad, but then you’ve got to negate working with knee-high water - sometimes deeper.
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"Having chosen this time of year, vegetation in this area doesn’t lend itself to manoeuvring - but then again, it’s all part of the realism.